The effect of pronunciation instruction on the speech of 29 adult speakers of other languages (Japanese, Arabic, Persian, Chinese, and Korean) with previous training in English as a second language was studied. Pronunciation improvement was compared in three groups: one receiving group pronunciation training, one receiving individualized pronunciation instruction, and a third control group receiving no pronunciation training. All subjects' speech was taped before and after the eight-week pronunciation course and evaluated by five judges. Results showed no significant difference in pronunciation improvement between the trained and untrained groups or between the group-trained and individually-trained students. However, the entire group showed some pronunciation improvement in the course of the study. This suggests that improvement in pronunciation occurs over time, but not necessarily as a result of formal training. (MSE)